Generator regulation



Nov. 27, 1923 1,475,251

R H. SULLIVAN I GENERATOR REGULATION Filed Dec. 15 1922 METAL F/LAME/VT lInventm Patented Nov. 27 1923. I 1,475,251 ,UNITED STATES. PATENT OFFICE.

RAYMOND H. SULLIVAN, OF ROCHESTER, NEW YORK, ASSIGN OR TO NORTH EAST ELEC- TRIC COMPANY, OF ROCHESTER, NEW YORK, A CORPORATION OF NEW YORK.

GENERATOR REGULATION.

Application filed December 15, 1922. Serial No. 607,099.

To all whom it may concern: reduce the electromotive force effective on Be it known that I, RAYMOND H. SULLI- the field-winding when the contacts of the VAN, a citizen of the United States, residregulator are open, while not appreciably ing at Rochester, in the county of Monroe affecting the field-winding when the con:

' and State of New York, have invented certacts are closed.

tain new and useful Improvements in Gen- The invention is more" particularly deerator Regulations; and I do hereby declare scribed in connection with the accompanythe following to be a full, clear, and exact ing drawing, which is a diagram of a bat description of the inventlon, such as will tery-charging system embodying the in- I 1o enable others skilled in the art to which it vention.

appertains to make and use the same. In .the illustrated embodiment of, the in- This invention relates to the regulation vention the generator 1 has main brushes of the output of electric generators of the 2 and 3, and a third or supplementary brush type in which the field-winding, instead of 4. The main brushes are connected with 15 being connected in. shunt across the main load-conductors 5 and :6. The field-windbrushes or terminals of the generator, is ing 7 is connected, at one end, with the third connected between one main brush and a brush 4, while its other end is connected third or supplementary brush. with the conductor 5 and the main brush A generator of the third-brush type, when 2. A storage-battery 8 is connected across 2o driven at variable speed and connectedconthe conductors 5 and 6, and a reverse-cur- '75v stantly with a storage-battery, is self-regurent cut out 9, of any ordinary or suitable lating to the extent that its output does not form, may be interposed in one of the load become excessive at anyspeed. Both Voltage conductors, to prevent discharge of the batand quantity of the output are variable, tery when the generator is at rest. 25 however, and accordingly additional regu- The regulator is or may be of ordinary lating means are sometimes used with such form, comprising a magnet 10 which is ena generator, such means having usually the ergized by current from the load-conducform of an electro-magnetic vibratory detors. The armature 1-1 of the regulator vic'eby-which the circuit through the fieldcooperates with a fixed contact 12, which 30 winding is rapidly opened and closed, at is connected, by a wire 13, with the conduca rate depending on the characteristic of tor 5. A resistor 14 is connected-in shunt the generator output which it is desired to with the contacts of the relay. I control. V The apparatus, as so far described, is in A vibratory regulator for the purpose in accordance with prior practice, and the 35 question suffers from the difiiculty that its present invention resides in the use of a U0 contact-points heat and burn away rapidlysecond resistor 15 which is connected be- F or that reason it is customary to connect tween the wire 13 and the conductor 6. a resistor in shunt with the contact-mem- This resistor has preferably a substantially bers of the regulator, to carry the heavy higher resistance than the resistor 14, and, 1 (0 induced current occurrin at each separait may be of any ordinary form or matetion of the contacts ince this resistor rial. It is shown, however, as a lamp havafi'ords van alternative path for current ing a filament of tungsten or other refracthrough the field-winding, it limits the tory metal. The resistor 14 may have a effectiveness of the regulator if it be of resistance sufficiently low to protect. the p 45 10w resistance, while its effectiveness to contacts against destructive sparking.

- protect the contacts is slight if. it be of This apparatus'operates as follows: So highresistance. I 1 long as the voltage across the load-conduc- The object of the present invention'is 'to tors remain within the predeterm'ned produce a system, of the kind just described, amount the contacts of the regulato rein which the contacts of the regulator shall main closed, thus affording a path of low be effectively protected from the burning resistance for current flowing between the effect of the interrupted current without brushes 4 and 5 and through the fieldreducing the effectiveness of the re lator; winding. Current also flows through the This is accomplished by the use 0 a secresistor lfi, but this current is so small in o resistbr, which is so arranged as to amount that it does not substantially afiect the operation of the generator.

contacts close again, and this cycle If now the voltage rises above normal, the regulator-contacts are drawn apart, thus opening the circuit through the field-winding, eX- cept for the resistor 14. This momentarily weakens the field and cuts down the output of the generator, whereupon the regulator- 13 rapidly repeated so as to maintain the output-voltage of the generator at an average equal to the required amount.

The effect of the resistor 15 during this operation of the regulator is to afford a bypass for a part of the current passing through the resistor 14, when the regulatorcontacts are open. In so doing it deprives the field-windng of a part of the current which it would otherwise receive, thus giving the equivalent, so far as the effectiveness of the regulator is concerned, of a higher resistance in the resistor 1 1.

The use of a metal-filament lamp as the resistor 15, while not essential, is particularly 'advantageous,ow':ng to the high positive temperature cooflicient of resistance of the refractory metal of the filament. This J lamp should be of a rating such that when the regulator-contacts are open it will carry the current passing through it at that time without being raised to incandescence. When the regulator-contacts are closed, on the other hand, the increased through the lamp raises the temperature and the resistance of the filament, and this ZIIOI'GELSG/ is thereby limited and the loss of energy isminimized. In the same way the mtensity of the current which must be broken by the regulator contacts is limited.

It will be apparent that the ultimate effect of the resistor 15 is to permit the regulator, without loss of effectiveness, to operate in conjunct'on with a smaller resistance at 14 than could otherwise be used, and that this has the effect of diminishing sparking by afi'ording a more effective path for the induced current from the field-winding. This result is to some extent counteracted by the fact that the contacts have to interrupt, in part, the current flowing through inany well known manner,

current the resistor 15, but since this resistor is non-inductive, interruption of the current .through it produces relatively little sparkan automobile, having a rating of 12 volts,

the resistor 14; may suitably have a resist: ance of about 5 ohms and the resistor 15 0t 12 ohms. A 15 candle-power 1'2-volt tungsten lamp may be used for the latter, and a lamp of 32 candle-power may also be used as the resistor let with good results.

The regulator is shown diagrammatically as connected with the load-conductors in such a manner as to act to maintain a constant voltage in the generator-output, but it will be apparent that it may be arranged, to control the generator with respect to quantity of output or with respect to some function of quantity and voltage.

The invention claimed is:

1. The combination, with an electric generator having main brushes, a third or auxiliary brush and a field-winding of which one terminal i connected to the third brush, a resistor connecting the second terminal of the field-winding with one of the main brushes, and a vibratory regulator arranged to shortcircuit said resistor intermittently in, accordance with variations in a characteristic of the output of the generator, of a second resistor connecting said second terminal of the field-winding with the other main brush of the generator.

2. The combination set forth in claim 1, characterized further by the fact that said second resistor has a high positive temperature coefficient of resistance.

3. The combination set forth in claim 1, characterized further by the fact that said second resistor has a substantially higher resistance than the first said resistor.

RAYMOND H. SULLIVAN. 

